JavaScript · Browser + Node.js · From $20
Do My JavaScript Homework
JavaScript is the one assignment language graded in two hostile runtimes at once. Code that passes node solution.js can still fail a headless-browser DOM test. A working JS developer writes to the exact runtime in your brief, so the same file the autograder runs is the file we test.
Runtime-matched · Passes npm test · Pay 50% after it runs
What we cover
The full JavaScript toolchain your course grades on
The grader rarely tests raw syntax. It runs your package.json scripts, lints with ESLint, and checks the DOM with a headless browser. We cover every piece of that chain, from the Fetch API to the event loop.
Whichever stack your brief names, the developer works in it daily. Vanilla document APIs for a CS193X core project. React hooks for a CS50W capstone. Express routes plus Postman checks for a Node API. We do not template one stack onto another.
The async core is where most marks live, so we treat it carefully. A fetch wrapped in async and await, errors caught, and the event loop understood well enough to know why a setTimeout with delay 0 still runs after a synchronous log. That mental model is the difference between code that works by accident and code that survives the hidden tests.
Do my JavaScript assignment
Four JavaScript assignments we build end to end
An assignment is the graded artifact, not a one-line fix. These four cover most coursework, from a vanilla DOM app to a full React and Express capstone. Each one ships tested against the suite your course attaches.
Vanilla-JS DOM app with persistence
A to-do list or shopping cart built with only document APIs, addEventListener, and localStorage through JSON.stringify and JSON.parse. No jQuery, no framework, because courses like Stanford CS193X ban them on the core. Graded on event delegation, zero global leaks, and state that survives a reload. We delegate clicks off a single parent node with createElement and dataset attributes, so adding a row never rebinds a listener and the markup stays clean for the structure check.
Fetch an API and render the result
An async function that fetches JSON from a public REST API, handles the Promise and the error path, and injects the result into the DOM. Marked on await correctness, the loading and error states, and no unhandled rejections crashing the tab. CORS and a non-200 response are the two things that silently break this brief, so we check response.ok before parsing and render a real error message instead of a blank screen.
Node and Express REST endpoint
A CRUD server with app.get, app.post, app.put, and app.delete, JSON request and response bodies, and the right status codes: 200, 201, 400, 404, 500. Verified by a Jest or Supertest suite that hits each route. Middleware order is where these lose points, so express.json() runs before the routes and the 404 handler sits last, after every defined path.
React single-page app
Components with useState and useEffect, lifted state, and conditional rendering. The CS50W Commerce and Pizza capstones pair a React front end with a Node and Express or Django back end. We build the whole slice. Stale closures and a missing useEffect dependency array are the two bugs graders probe, so effects list every dependency and event handlers read state through the functional updater, not a captured value.
JavaScript assignment help
Help scoped to how your assignment is actually scored
JavaScript assignment help here means matching the grader, not guessing at it. Autograders run Jest or Mocha suites on Gradescope, CodeGrade, or GitHub Classroom. UI work gets checked with jsdom, Puppeteer, or Selenium. Lint cleanliness is its own scored line.
So the help covers three layers. The logic that makes npm test pass. The lint gate that costs points on no-var and eqeqeq. And the runtime match, because a passing Node script can still fail a DOM test. We hand back code that clears all three.
Version matters more in JavaScript than students expect. A top-level await needs an ES module and a recent Node. Optional chaining and ?? need a modern target or a Babel transpile step. We write to the ECMAScript edition your course assumes, anywhere from ES6 through ES2023, and set the bundler config so the code that ships is the code the grader can run.
JavaScript homework help
The six JavaScript bugs we fix every week
Weekly homework breaks in predictable ways. These six account for most of the failed submissions we see. Each one has a known fix and a comment so you can explain it.
this is undefined or bound to the wrong object
Passing a method as a callback drops its receiver, so `this` resolves to undefined in strict mode. The fix is an arrow function, a `.bind(this)`, or a class arrow-field handler. We also write the viva answer for why it resolves that way.
A var-in-loop closure captures the final value
Every setTimeout or event callback reads the last loop value, so a loop over 0 to 9 logs 10 ten times. The fix is one keyword: declare the loop variable with `let` so each iteration gets its own block scope.
An unhandled Promise rejection or a forgotten await
A fetch chain with no await or no .catch resolves out of order or crashes the Node process. We await inside try/catch, attach .catch, and guard with Number.isNaN instead of the global isNaN.
NaN poisons every downstream calculation
Arithmetic on a fetched string or an undefined field yields NaN, and because `NaN === NaN` is false the bug hides until the total reads NaN. We coerce with Number() or parseInt(x, 10) and guard with Number.isNaN.
Loose == coercion creates phantom equality
With `==`, the engine treats `0 == ""`, `null == undefined`, and `[] == false` as true. We use strict `===` and `!==` everywhere, which is the eqeqeq rule your ESLint config scores.
A CommonJS and ESM module mismatch throws on load
Mixing require() with import, or missing `"type": "module"` in package.json, throws "Cannot use import statement outside a module" or "require is not defined". We pick one module system and set the package.json `"type"` to match the runtime in your brief.
// before: passes "node solution.js", 0/100 on the jsdom DOM tests
// after: setTimeout uses let, this is bound, npm test is green
//
// for (var i = 0; i < buttons.length; i++) { ... } // logs 10, 10, 10
// for (let i = 0; i < buttons.length; i++) { ... } // logs 0..9 ✓ fixed
//
// "I could finally explain how 'this' resolved in my viva."
// - web programming student, 2026What you get
A delivery you can run, defend, and submit
A clean package.json and lockfile
Dependencies pinned, the right "type" field set for your runtime, and the npm scripts the grader invokes (npm test, npm start, npm run build) wired and working.
A green test run before delivery
We run your Jest, Mocha, or Supertest suite on your Node version and ship only when it passes. If you have no suite, we add one so you can prove the code works.
Commented, ESLint-clean code
Every file passes eslint:recommended or Airbnb with no-var, eqeqeq, and no-unused-vars satisfied, and each non-obvious line carries a comment you can read in a viva.
A run guide and viva answers
Exact commands and the Node and npm versions, plus two or three questions a grader asks about closures, this-binding, or the event loop, with answers.
Help with JavaScript homework
From your brief to a quote in 15 minutes
Send the assignment PDF, the rubric, and three details: your Node version, the runtime target (browser or Node), and the module system (ESM or CommonJS). A JavaScript developer reads it and sends one fixed price.
Send the brief and your runtime
The assignment, the rubric, your Node version, and whether it runs in the browser or Node.js. One short form, no account.
Get a fixed quote in 15 minutes
A developer who writes JavaScript daily reads the brief and sends one price. No hourly meter, no rush fee.
Pay half, then we write and test
Approve the quote, pay 50% to start, and message the developer while they work. We run npm test before delivery.
Pay the rest after it runs
Run it on your machine and your Node version. Pay the second 50% only once it is green. 7 days of free revisions either way.
Help with JavaScript assignment
Course-specific help, matched to the autograder
JavaScript shows up at three course levels, and each has its own rules. We honor them. Harvard CS50W with its named projects (Commerce, Pizza, Network, Mail, Capstone). Stanford CS193X, which bans front-end frameworks on the core. Stanford CS253 Web Security, where JavaScript powers the XSS and CSRF exercises.
The grading format matters as much as the code. UCSB runs a Jest autograder on Gradescope. GitHub Classroom runs npm test. CodeGrade wires Jest, Mocha, and Selenium together with an ESLint score. We build to whichever one your course uses, then verify against it before delivery. Plagiarism checks with MOSS and Turnitin pass because every line is written fresh for your brief.
Pricing
One fixed price per assignment, from $20
Priced by complexity, not by a meter. A single DOM script sits at the low end. A React and Express capstone with a Jest suite sits at the top. You see the full number before you pay, and there are no rush fees.
JavaScript homework help
Questions, answered
Straight answers about runtimes, autograders, frameworks, and the bugs that cost rubric points.
Will the code run in the browser or in Node.js? +
Whichever your brief states. We match the runtime, the module system (ESM import vs CommonJS require), and the package.json `"type"` field exactly, so the same file the grader runs is the file we test.
Can you make my assignment pass the Jest or Gradescope autograder? +
Yes. We run your provided test suite with `npm test` before delivery and ship only when it is green on the Node version named in your brief.
Do you use jQuery or only vanilla JavaScript? +
Vanilla document APIs by default, since courses like CS193X ban jQuery and React on the core. We reach for a framework only when your rubric requires one.
My `this` is undefined and my setTimeout logs the wrong number. Can you fix it? +
Yes. Those are a binding bug and a var-closure bug. The fix is arrow functions or `.bind` for the first, and a `let`-scoped loop variable for the second. We hand back the corrected code with a comment on each.
Can you build a React app with hooks for my final project? +
Yes. Components with useState and useEffect, lifted state, and a Node and Express or Django back end for CS50W-style capstones. Multi-milestone projects ship with a staggered commit history.
Will it pass ESLint without warnings? +
Yes. We deliver clean against eslint:recommended or the Airbnb config, including no-var, eqeqeq, and no-unused-vars, because lint is a scored rubric line, not a suggestion.
Can you write the Express REST API and its tests? +
Yes. CRUD routes with the correct 200, 201, 400, and 404 status codes, plus a Jest or Supertest suite that exercises each endpoint and the error paths.
Will fetching the API break with async errors? +
No. We await inside try/catch, render explicit loading and error states, and guard against unhandled Promise rejections so a slow or failed request never freezes the page.
Related help
Other languages and the programming hub
Moving JavaScript to a typed codebase, or comparing it with a compiled language? These pages cover the next step.
Get a fixed quote for your JavaScript assignment
Send the brief and your Node version now. The first reply is free, and you pay nothing until you approve the price.